Boring type continuous mining machine with contour cutters



Oct. 22, 1968 E. F. BRILL ETAL 3,407,006 BORING TYPE CONTINUOUS MINING MACHINE WITH CONTOUR CUTTERS Filed May 2, 1966 4 Sheets-Sheet i ATTORNEYS Oct. 22, 1968 E. F. BRILL ETAL. 3,407,006

BORING TYPE CONTINUOUS MINING MACHINE WITH CONTOUR CUTTERS Filed May 2, 1966 4 Sheets-Sheet 2 Q q INVENTORS EdWrdFEzj 'ZZ fiozzla'zdfil'fiizglqy BY a Z ATTORNEYS Oct. 22, 1968 E. F. BRILL ETAL 3,407,006

BORING TYPE CONTINUOUS MINING MACHINE WITH CONTOUR CUTTERS Filed May 2, 1966 4 Sheets-Sheet 3 m"% qyw ATTORNEYS Oct. 22, 1968 E. F. BRILL ETAL BORING TYPE CONTINUOUS MINING MACHINE WITH CONTOUR CUTTERS 4 Sheets-Sheet 4 Filed May 2, 1966 ENE I fzgZe y ATTORNEYS 3,407,006 BURING TYPE CONTINUOUS MINING MACHINE WITH CONTOUR CUTTERS Edward F. Briil, Oconomowoc, Wis., and Howard Shelley, Niles, llL, assignors to Westinghouse Air Brake Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed May 2, 1966, Ser. No. 546,974 18 Claims. (Cl. 29959) ABSTRACT OF THE DISCLOSURE Boring type continuous miner having at least two rotary boring heads and contour cutters rotatable about the axes of the boring heads concurrent with rotation of the boring heads. The contour cutters move in and out during rotation thereof in a sequence which varies about the bore and intersects the bore in at least one cutting position of the contour cutters to modify the cross-section of the bore to a pre-selected contour. The cutting patterns of the contour cutters may be independently adjustable with respect to each other and the contour cutter is adjustable as the main cutter is adjusted to vary the size of the bore.

Background of the invention This invention relates to continuous mining machines having a pair of rotary boring arms mining contiguous intersecting bores in a mine face, and is particularly directed to improvements in such machines wherein the circular contours mined by the boring arms are modified to predetermined forms.

In continuous boring mining operations, continuously mining coal and other materials such as salt, gypsum, potash and the like, in which contiguous intersecting bores of a circular contour are mined in a mine face, and the corners and cusps between the bores are trimmed by trimmer cutter chains and like trimming devices, when mining in relatively low seams the mining heads are usually spaced farther apart to compensate for reduction in height of the bore, in order that the machine may mine working places of adequate width. This increased spacing of the mining heads requires a wider support structure for the mining heads and, therefore, presents a problem of adequate ventilation space between the support structure for the mining heads and the ribs of the working face, in addition to the problem of mining suflicient floor space for tramming clearances for the continuous traction tread devices, supporting and propelling the machine, and in many cases increases the size of the cusps left between the boring heads with the problem of adequately trimming the roof and floor of the mine and reducing the cusps to a size where they may readily be loaded. Heretofore these problems have been partially alleviated by mining the cusps and widening the bore at the floor and roof of the mine by the trimmer chains following the boring heads and trimming the floor and roof of the mine.

Trimmer chains, however, while extremely satisfactory in many ways add to the difficulty of picking up the mined coal by the conveyor of the machine and also materially States Patent D F 3,407,006 Patented Oct. 22, 1968 add to the cost and maintenance of the machine, and do not serve to break up the cusps to the extent required for loading, where the spacing between the boring heads is relatively wide.

Summary and objects of invention With the foregoing considerations in mind, it is an object of the present invention to provide a novel and improved form of boring type miner, in which contiguous bores of a circular contour are mined by rotary boring heads, and in which increased ventilation space and tramming clearance as well as a material reduction in size of the cores between the boring heads is attained by contour cutters following the boring heads and trimming the circular bores to a predetermined non-circular contour.

Another object of the invention is to provide a novel and improved form of rotary boring head particularly adapted for continuous mining machines, in which cutter bit carrying cutter supports mine a bore of a circular contour and contour cutters follow the cutter supports and are rotated by the boring head and translationally moved with respect to the boring head, to modify the circular bore in accordance with mining requirements.

A further object of the invention is to provide an im proved form of rotary boring head including a rotating boring arm extending diametrically of the axis of rotation of the boring head and having cutter supports projecting forwardly therefrom, in which a contour cutter is extensibly and retractibly mounted on the boring head and follows the cutter bit carrying supports and rotates therewith, to modify the circular contour mined by the cutter bit carrying cutter supports.

Still another object of the invention is to improve upon the continuous mining machines in which a plurality of parallel contiguous bores are mined in a mine face, by providing at least one contour cutter on each boring head, trailing the cutters which mine a circular bore in the mine face, and simultaneously adjusted with the cutters to vary the diameter of the bore, and moved in and out relative to the axis of rotation of the cutters by rotation of the boring head, to mine preselected areas radially beyond the reach of the boring cutters.

A still further object of the invention is to improve upon the rotary boring types of continuous mining machines mining contiguous bores in a mine face, by providing supplemental contour cutter means in association with the boring heads of the machine, in which cam and follower means translationally move the supplemental contour cutter means as they rotate, to mine preselected areas radially beyond the reach of the boring heads.

A still further object of the invention is to provide a novel and improved mining system in which oppositely rotating boring heads mine circular bores in a mine face and in which the contours of the circular bores are modified by supplement-a1 contour cutter means rotating with the boring heads and providing the clearance required for tramming and ventilation and reducing the size of the cusps between the boring heads.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherem:

FIGURE 1 is a diagrammatic front end view of a continuous mining machine constructed in accordance with the principles of the present invention looking at the machine toward the front end thereof and showing the machine in the operation of mining a mine face;

FIGURE 2 is a diagrammatic view diagrammatically illustrating the cutting pattern of a continuous boring machine constructed in accordance with the teachings of FIGURE 1, having widely spaced outer boring heads and a central leading pilot cutter;

FIGURE 3 is a diagrammatic view illustrating the cutting pattern of a boring machine like that shown in FIGURE 1 with the boring heads spaced sufficiently close to each other, to mine intersecting bores in the mine face;

FIGURE 4 is a top plan view of a boring head, such as is diagrammatically illustrated in FIGURE 1;

FIGURE 5 is a sectional view taken substantially along line 55 of FIGURE 4; and

FIGURE 6 is an end view of a boring head looking at the boring head towards the front end thereof, with the pilot cutter and intermediate cutter supports not shown, for the purpose of more clearly illustrating the means for translationally moving the contour cutters with respect to the circular boring cutters.

In the embodiment of the invention illustrated in the drawings, I have diagrammatically shown in FIGURE 1, a front end view of a continuous mining machine 10, of the rotary boring type. The machine is supported on the usual laterally spaced continuous traction tread devices 11, 11 which serve to tram the machine from working place to working place and to feed a pair of rotary boring heads 12, 12 into the working face of a mine. The continuous traction tread devices 11 may be of a conventional form and may be driven from individual motors and speed reducers (not shown), in a manner well known to those skilled in the art and are no part of the present invention, so need not herein be shown or described further.

The rotary boring heads 12, 12 are rotatably mounted on a cutter frame structure 13 for rotation about parallel horizontal axes extending perpendicular to the working face of the mine and are driven from electric motors (not shown) mounted on said cutter frame structure. Usually an individual motor is provided for driving each boring head and the drives to the boring heads are housed in the cutter frame structure and tied together to time the two boring heads to rotate in timed relation with respect to each other and to avoid interference between said boring heads. The motors and geared drive connections to the boring heads are conventional, so need not herein be shown or described further.

A conventional form of conveyor 15 is also shown as extending beneath a throat 16 of the cutter frame structure, 13, for picking up and conveying the cuttings mined by the boring heads 12, 12 to the rear of the machine for loading onto shuttle cars, a conveyor, or other conventional material carrying means.

Suitably mounted on the cutter frame structure 13 for trimming the cusps projecting upwardly of the floor and depending from the roof of the mine between the boring heads 12, 12 are lower and upper rotary cutter bit carrying cutter bars 17 and 18. The respective rotary cutter bars 17 and 18 may be mounted on the cutter frame structure 13 for vertical adjustable movement with respect thereto in a conventional manner, to conform the rotary cutter bars to the cutting diameters of the boring heads 12, 12. The rotary cutter bars 17 and 18 may be driven by individual motors (not shown) in directions to progress the cuttings toward the conveyor 15 of the machine, in a manner well known to those skilled in the art, so not herein shown or described further.

Referring now in particular to the detailed construction of the rotary boring heads 12, 12, said boring heads are each of the same construction, so one only need 4 herein to be shown or described in detail. The boring head, 12, as shown in FIGURES 4 and 5, includes a hollow drive shaft 21 suitably journalled in a hub 22, projecting forwardly of the cutter frame structure 13, to one side of the longitudinal center line of the machine.

An annular support and retainer 23 abuts and has interengagement with the forward end of the hub 22 and is suitably secured thereto and extends forwardly therefrom. As shown in FIGURE 5, the annular support and retainer 23 extends about the hollow shaft 21 and has an inwardly stepped front annular face 24, facing boring arms 25 of the boring head. The boring arms 25 extend diametrically of the hollow shaft 21 and terminate in equally spaced relation with respect to the axis of said shaft. The annular face 24 has an outer annular recess 26 for a seal 27 recessed in a corresponding facing annular seal recess 29 in the boring arms 25.

The boring arms 25, are shown in FIGURE 4 as being in two sections, including a rear frame section 30, shown as formed integrally with the shaft 21 and extending diametrically of said shaft in opposite directions and a front frame section 31 forming a forward continuation of said rear section, and bolted or otherwise secured thereto.

The front section 31 of the boring arms 25 is shown as having parallel spaced bores 32, 32 extending perpendicular to the axis of rotation thereof and on opposite sides of said axis of rotation. The bores 32, 32 form mountings for oppositely extensible telescopic arms 33, 33, offset laterally from the axis of rotation of said boring head and mounted in said bores for adjustable movement therealong. Each telescopic arm 33 is generally cylindrical in cross-section and generally conforms to the bore 32. A key 35 recessed in the telescopic arms and extending outwardly therefrom cooperates with a keyway 36, extending along the bore 32 to hold said telescopic arm from rotation.

A separate cutter support 37 is secured to the outer end of each telescopic arm 33 and extends forwardly therefrom. Each cutter support 37 conforms to the mean diameter of circular bore to be mined and has conventional cutter bits 43 projecting therefrom and patterned to cut clearance for said cutter support in all positions of radial adjustment thereof. As shown in FIGURE 5, the cutter support 37 extends rearwardly of the arm 33 about an extensible support arm 39 for a contour cutter 40, and is journalled on said extensible support arm on a bearing 41, retained to said cutter support as by an annular retainer 42.

The boring head 12 also has a central pilot cutter 45 having cutter bits 46 projecting therefrom and an intermediate cutter support 47 having cutter bits 48 projecting therefrom. The central pilot cutter 45 and intermediate cutter supports 47 are of conventional forms commonly used on rotary boring heads of continuous mining machines, and are only shown diagrammatically in FIG- URE 1. The pilot cutter and intermediate cutter supports have been omitted from FIGURES 5 and 6 in order to avoid confusion.

The telescopic arm 33 has a generally cylindrical hollow portion 50 extending for a portion of the length thereof and opening to the opposite end of said arm from the cutter support 37. An adjustment screw 51 threaded in a nut 53 extends within the hollow portion 50 of the telescopic arm 33. The nut 53 is secured to the opposite end portion of the telescopic arm 33' from the cutter support 37 as by machine screws 54. The threaded shaft 51 has a reduced outer end portion 55 extending outwardly beyond the nut 53 and having a spur gear 58 keyed or otherwise secured thereto. The reduced end portion of the threaded shaft 51 is journalled in a bearing support 56 on a bearing 57. Thrust bearings 59, shown in FIG- URE 3, as being roller types of radial thrust bearings, are interposed between the shoulder formed by the reduced end portion 55 of the threaded shaft 51 and the bearing support 56, and between the inner face of the gear 58 and the outer face of the bearing support 56. The gear 58 meshes with a spur gear 60 having elongated teeth and shown as being splined to the end of a shaft 61. The shaft 61 is journalled in a bearing support 62 formed integrally with the front frame section 31 of the boring arm. Axial thrust bearings 63, at opposite ends of the bearing support 62, are shown as being provided to take up on end thrust of the shaft 61.

The shaft 61 has a worm gear 65 keyed or otherwise securedto its inner end and driven from a worm 66 on the inner end of a worm shaft 67 (FIGURE 4). The worm shaft 67 is suitably journalled in a bearing support 69 coaxial with the axis of rotation of the hollow shaft 21, and extends inwardly of said bearing support and hollow shaft within the cutter frame 13. A suitable motor, such as a hydraulic motor (not shown), may be provided to drive the shaft 67 and worm 66. The worm 66 meshing with and driving worm gears 65 on opposite sides of the axis of rotation of said worm, may thus ad-justably extend and retract the two cutter supports 37, offset from opposite sides of the axis of rotation of the boring head 12, equal amounts. It should here be understood that one shaft 61 extends from the Worm gear in one direction and the other shaft 61 extends from its worm gear in an opposite direction to accommodate adjustment of the cutter supports 37 together, and that the adjustment mechanism for each cutter support and telescopic arm is the same, so one only need herein be shown and described in detail.

Each telescopic contour arm 39 is slidably mounted in a separate sleeve 70 for adjustable, extensible and retractible movement with respect thereto. Each sleeve 70 is in turn, mounted in a separate cylindrical cavity or bore 71 extending along the boring head to one side of the axis of rotation thereof. The two cavities 71 are thus on opposite sides of the axis of rotation of the boring head and support the contour telescopic arms for extensible and retractible movement with respect to the axis of rotation thereof, in the same directions as the cutter supports 37, 37. One half of each cylindrical cavity 71 is shown as being formed in the rear section 30 of the boring head and the other half is shown as being formed in the front section 31 of the boring head, the complete cavities being formed by the mating of the two parts of the boring head, and the bolting of the parts together. The adjustment means for the contour telescopic arms on each side of the boring head is the same, so only one contour telescopic arm and its adjustment means need be shown and described in detail.

Bearings 72 and 73 are provided to accommodate translational movement of the associated sleeve 70 along the cavity 71. An annular end cap 74 extends about the telescopic arm 39 and forms a mounting for sealing means for said arm and bore. The inner end of the telescopic arm 39, like the inner end of the arm 33, is hollow. An adjustment screw 75 extends within the hollow portion of said telescopic arm 39 and is threaded in a reduced diameter inner end portion 76 of said telescopic arm, The threaded reduced diameter end portion 76 forms a nut movable along said adjustment screw, to extend or retract the telescopic arm 39 and the contour cutter 40 extending from the end thereof. The telescopic arm 39 is mounted in the sleeve 70, for adjustable, extensible and retractible movement with respect thereto, on bearings 77 and 79, and is held from rotation with respect to the sleeve 70 as by diametrically opposed keys 80, slida'bly movable along key slots 81, formed in the inner periphery of the sleeve 70. The adjustment screw 75 has a reduced end portion 83 extending beyond the inner end of the sleeve 70 and suitably journalled inan end cap 84 for said sleeve. A spur gear-85 is keyed or otherwise secured to the reduced end portion -83 of said adjustment screw 75 and meshes with the elongated teeth of the spur gear 60 and is driven from said spur gear to adjustably extend or retract the contour cutter 40 with respect to the boring head 12, simultaneously with adjustment of the associated cutter support 37.

The contour cutter 40 on the outer end of the telescopic contour cutter arm 39 is shown as including a cutter support 88 having cutter bits 89 positioned to face and cut in the direction of cutting of the cutter bits on the associated cutter support 37.

The sleeve 70 is held from turning movement about its longitudinal axis, by a roller 90 on a shaft 91 connected with said sleeve for extensible and retractible movement therewith. The roller 90 extends within a slot 92 formed in the boring head, and shown as being longer than the stroke of said sleeve and the contour support arm 39. The shaft 91 may be mounted at its inner end on a support 94 for follower rollers 95, 95. The support 94 is shown in FIGURES 5 and 6 as extending partially about the inner end portion of the sleeve 70. Said support may be welded or otherwise secured to said sleeve. The shaft 91 in turn extends diametrically of said sleeve and has the roller 90 journalled thereon.

Referring now in particular to the means cooperating with the follower rollers 95 for translationally moving the contour cutters 40 along the axes of the cavities 71, a cam track 96 is formed in the front face 24 of the annular support and retainer 23. As shown in FIGURE 6 the cam track 96 is in the form of an irregular bearing face engaged by the follower rollers 95, 95 and effecting extensible movement of the contour cutter 40. The cam track 96 terminates at its inner end into a forwardly opening groove 97, opening toward the boring head 12 and receiving the innermost follower roller 95 and effecting retractible movement of the contour cutters 40.

The follower roller support 94 extends between the two follower rollers 95, to space said rollers apart and also extends beyond the inner roller 95, and has an arm portion 99 extending within the groove 97 along the inner side of the inner roller 95, and forming a bearing mounting for a support pin 100 for said follower rollers.

As shown in FIGURE 6, the cam track 96 is spaced radially from and extends about the hollow shaft 21 and is provided with four peaks 101 having valleys therebetween. The form of the cam track, however, may be tailored to individual requirements depending upon the spacing of the boring heads and the requirements for roof support, ventilation area and reduction of the cores for the particular conditions in which the boring heads are operating, to translationally move the contour cutters radially beyond the reach of the cutter supports 37, to mine preselected areas which cannot be mined by the cutter supports 37.

In FIGURE 5 we have shown one contour cutter 40 in its fully extended position. The opposite contour cutter (not shown) is in the same position. We have also shown the extreme in-position of the opposite contour cutter by dot dash lines. Upon rotation of the boring head, the cam track 96 and followers 95 will thereby extend the contour cutters 40 beyond the reachers of the cutter supports 37 during certain phases of the cycle of rotation of the boring heads, and during this extensible and retractible movement of the contour cutters, the spur gears 85 will slidably move along the elongated teeth of the associated spur gears 60, held from rotation by the worm 66 and worm gears 65.

In an operation of mining, the two cutter supports 37, 37 are adjusted to the required cutting diameter of the circular bore to be mined. The gears 60 will at the same time extend or retract the contour cutters 40 a corresponding amount. The two boring heads are then rotatably driven and advanced into the mine face by the continuous traction tread devices 11, 11, in a conventional manner. During this rotational movement of the boring head, the cam track 96 will extensibly and retractibly move the telescopic contour cutter arms 39, to position the cutter supports 88 and cutter bits 89 to cut in preselected areas radially beyond the reach of the cutter sup- 7 ports 37 and cutter bits 43, in accordance with the contour or form of the cam track 96.

In the diagrammatic illustration of the invention shown in FIGURE 1, the cam track 96 is so formed as to position the contour cutters 40 to cut areas A beyond the reach of the cutter bits 43, 43 at the upper and lower corners of the seam. The cam track is also formed to extend the contour cutters 40 to mine the bulk of the hourglass core between the boring heads, as indicated by areas B. The areas A provide added space for ventilation and also provide added width for the continuous traction tread devices 11, 11. The areas B reduce the hourglass core left between the cutter supports 37 and cutter bits 43 to minimum sizes which may readily be mined by the rotary cutter bars 17 and 18 as the machine advances, which cutter bars progress the mined material onto the conveyor for continuous loading.

In FIGURE 2 we have diagrammatically illustrated a cutting pattern of the contour cutters particularly adapted-for more widely spaced boring heads, with a central small diameter boring head in-between the boring heads. In the cutting patterns of the contour cutter-s of the figure, the circular bore cut by each rotary boring head is enlarged equal amounts -by the contour cutters 40, as indicated by areas C, to form a generally rectangular bore with rounded corners along the roof and floor of the mine and to reduce the core between the boring heads above and below a circular bore D, made by a central cutter (not shown).

In FIGURE 3 we have shown still another cutting pattern in which the floor area is widened by the contour cutters 40, mining areas E to provide added tramming space and reduce the cores between the boring heads to a size which may readily be trimmed by rotary cutter bars 17 and 18. In this cutting pattern, the upper portion of the bore from the ribs to the roof of the working place is maintained circular, to provide roof support, in such seams as require this added support.

It should here be understood that the particular cam track shown in FIGURE 6 is shown for illustrative purposes only and would extend the contour cutters 40 to mine areas C beyond the reach of the cutter bits 43, and that various other forms of cam tracks may be provided in accordance with requirements necessary to pattern the bore to the form required for certain mining conditions.

It should further be understood that the apparatus of the invention is adapted for continuous mining machines having any number of boring heads and it not limited to the particular boring miner shown.

While we have herein shown and described one form in which the invention may be embodied, it may readily be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof.

We claim as our invention:

1. A rotary boring head particularly adapted for continuous boring operations comprising:

a rotatable hub,

main and supplemental cutters carried by said hub rotatable therewith,

the main cutter being effective to cut a bore in a mine face,

the supplemental cutter being supported for movement relative to the rotational axis of the hub,

and means for moving the supplemental cutter relative to the axis, concurrently with rotation of said hub, in a sequence which varies about the periphery of the bore and intersects the bore in at least one cutting position of the supplemental cutter, to modify the cross section of the bore.

2. A rotary boring head particularly adapted for continuous boring operations comprising:

a rotatable hub,

main and supplemental cutters carried by said hub and rotatable therewith;

and

the main cutter being effective to cut a circular bore in a mine face,

the supplemental cutter being supported for movement toward and away from the axis of the hub to intersect the circular bore in at least one cutting position of the supplemental cutter,

and means for moving the supplemental cutter, concurrently with rotation of said hub, in a predetermined sequence toward and away from the axis of said boring head, to modify the bore to a non-circular cross section.

3. A rotary boring head particularly adapted for continuous boring operations comprising:

a rotatable hub,

main and supplemental cutters supported by said hub and rotatable therewith,

the main cutter being effective to cut a bore in a mine face,

the supplemental cutter being movable relative to the axis of the hub concurrently with rotation thereof,

and means for moving the supplemental cutter radially into and out of the bore wall at predetermined rotational positions of the hub to thereby modify the cross section of said bore.

4. In a boring type miner having at least one main cutter-bit-carrying boring head mounted for rotation about an axis extending perpendicular to a mine face, to cut a bore in the mine face, the improvement comprising:

a supplemental boring head mounted for rotation about the axis in trailing relation with respect to the main boring head,

the supplemental boring head having cutter means thereon supported for movement relative to the axis,

and drive means for rotating the supplemental boring head and moving the cutter means thereof relative to the axis, concurrently with rotation of said main boring head, in a sequence which varies about the periphery of the bore and intersects the bore in at least one cutting position of the supplemental boring head, to modify the cross-section of the bore.

5. In a boring type miner having at least one rotary boring head rotatably driven about a horizontal axis extending perpendicular to a mine face and having at least one boring arm having a cutter bit carrying cutter support mounted thereon and extending forwardly therefrom, the improvements comprising:

contour cutter means carried by said boring head and rotatably driven concurrently with said boring head about the axis of rotation thereof,

and means moving said contour cutter means radially of the axis of rotation of said boring head toward and from said axis during rotation thereof to mine pre-selected areas coincident with the bore mined by said rotary boring head in certain cutting positions of the contour cutter means, and movable relative to the bore mined by said rotary boring head to mine pre-selected areas radially outwardly beyond the cutting path of said rotary boring head in certain other cutting positions.

6. A rotary boring head particularly adapted for continuous boring operations comprising:

at least one cutter support rotatably driven about a horizontal axis perpendicular to a mine face and having cutter bits projecting therefrom, for cutting a circular bore in the mine face, and

at least one contour cutter mounted in trailing relation with respect to said cutter bits,

means supporting said contour cutter for rotational movement about the axis of rotation of said boring head and for movement toward and from the axis of rotation of said boring head,

other means rotatably driving and moving said contour cutter toward and from the axis of rotation of said boring head,

and adjustment means for varying the cutter diameter in trailing relation .with respect to said, cutter. bit

carrying cutter support for rotation about the axis of rotation of said cutter bit carrying cutter support and rotatably driven concurrently with rotation of said boring head,

and means moving said contour cutter means toward and from the axis of rotation of said boring head concurrently with rotation thereof to mine pre-selected areas radially outwardly beyond the cutting path of said cutter bit carrying cutter and intersecting the cutting path of said cutter bit carrying cutter support in at least one cutting position of said contour cutter means.

8. A boring type miner in accordance with claim 7,

wherein adjustment means is provided to vary the cutting diameter of said cutter bit carrying cutter support, and

wherein said adjustment means coincidentally orients the contour cutter means relative to the boring diameter of said cutter bit carrying cutter support.

9. In a boring type continuous miner,

a rotary boring head,

a main supporting housing supporting said rotary boring head for rotation about a horizontal axis perpendicular to a mine face,

at least one cutter bit carrying cutter support projecting forwardly of said boring head in radially spaced relation with respect to the axis of rotation thereof and cutting a circular bore in a mine face,

a contour cutter carried by said boring head and having cutter bits on its outer end spaced radially of the axis of rotation of said boring head,

and means operated by rotatable movement between said boring head and said main supporting housing for moving said contour cutter toward and from the axis of rotation of said cutter bit carrying cutter support for cutting pre-selected areas radially beyond the reach of said cutter bit carrying cutter support and intersecting the cutting path of said cutter bit carrying cutter support in at least one cutting position.

10. The structure of claim 9,

wherein adjustment means is provided for radially adjusting said cutter bit carrying cutter support and simultaneously adjusting said contour cutter, to vary the cutting diameter of the boring head and orient the contour cutter relative to the cutting diameter of the boring head.

11. The structure of claim 10,

wherein the adjustment means holds said cutter bit carrying support and said contour cutter in adjusted relation with respect to each other and accommodates translational movement of said contour cutter with respect to said cutter bit carrying cutter support, to cut pre-selected areas radially beyond the reach of said cutter bit carrying cutter support.

12. The structure of claim 10,

wherein the adjustment means includes a gear selectively driven by power, separate parallel screw and nut means operatively connected with said cutter support and said contour cutter and rotatably driven by said gear to adjustably move said cutter and support and said contour cutter together,

and wherein the drive connections to the screw and nut means adjustably moving said contour cutter is slidable along said gear and is in mesh therewith in all positions of translational movement of said contour cutter with respect to said gear. 13. The structure of claim 10, wherein a drive shaft extending perpendicular to a mine face and coaxial 0f the bore to be driven therein forms a support for said rotary boring head, wherein the rotary boring head extends diametrically of said drive shaft and terminates at its opposite ends,

equal distances from the center of rotation of said shaft, 1

wherein cutter bit carrying supports extend forwardly of diametrically opposite ends of said boring head, for cutting a circular bore in a mine face, and

wherein a contour cutter is associated with each cutter bit carrying cutter support and is mounted in said boring head for rotation therewith and for extensible and retractible movement with respect thereto.

14. The structure of claim 12,

wherein the cutter bit carrying cutter supports and contour cutters are mounted in said boring head for extensible and retractible adjustable movements with respect thereto to vary the cutting diameter thereof,

wherein common drive means are provided for simultaneously adjustably moving said cutter bit carrying cutter supports and contour cutters,

and wherein the common drive means includes drive gears adjustably moving said contour cutters and accommodating translational movement of said contour cutters to mine radially beyond the reach of said cutter bit carrying cutter supports.

15. The structure of claim 12,

wherein adjustment means are provided for simultaneously adjusting the contour cutters and cutter supports with respect to the axis of rotation of the boring head and comprise individual nuts and adjustment screws for each of said cutter supports and for each of said contour cutters,

wherein the nuts and adjustment screws for one cutter bit carrying cutter support and for an associated contour cutter are on one side of the axis of the boring head, and the nuts and adjustment screws for an opposite cutter bit carrying cutter support and an associated contour cutter are on the opposite side of the axis of rotation of the boring head,

and wherein common drive means are provided for each pair of adjustment screws on each diametrically opposed end of said boring head and include drive gears rotatably driving said adjustment screws, and a gear for driving each pair of drive gears and having teeth of sufiicient length to accommodate translational movement of said contour cutters, to mine radially beyond said cutter bit carrying cutter supports, and to adjust said contour cutters in the various positions of extension and retraction thereof.

16. In a boring type of continuous mining machine,

a main supporting housing supported for movement about the ground,

at least two rotary boring heads supported on said main supporting housing for rotation about axes perpendicular to a mine face,

means rotatably driving said boring heads,

said boring heads each including a hub and main and supplemental cutters carried by said hub,

the main cutters being effective to cut a circular bore in a mine face,

the supplemental cutters being supported for movement toward and from the hub to intersect the circular bore in certain cutting positions thereof, and

means moving the supplemental cutters independently of each other towards and from the axes of said hubs concurrently with rotation of said hubs, to modify the contour of the bore in accordance with pre-selected cutting patterns.

17. The structure of claim 16,

wherein adjustment means is provided for varying the cutting diameters of said cutters, and

wherein said adjustment means coincidentally orients the supplemental cutters relative to the cutting diameters of said main cutters.

18. The structure of claim 16,

wherein the means moving the supplemental cutters independently of each other towards and from the axes of the hubs comprise an individual cam for each supplemental cutter and operative connections between said cams and cutters.

12 References Cited UNITED STATES PATENTS Re. 24,479 6/1958 Graham 299-59 5 3,108,788" 10/1963 Allimann 299-60X FOREIGN PATENTS 1,321,556 2/1963, France.

118,437 4/1958- USSR.

10 ERNEST R. PURSER, Primary Examiner.

UNITED STATES PA'IENI OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 407, 006 Dated OCtObZI' 22, 1968 Inventor s Edward F. Brill and Howard E. Shelley It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

the first occurrence, to --this.

Column 7, line 23, change Column 10, after line 10, insert -wherein a non-rotatable sup port is provided for said shaft;

same column, line 21, change "movements" to -movement--;

same column, line 40, after "axis, insert --of rotation-.

bib-$1.9 fins) SEALED FEB 1 71970 Q mtest: a 35M 1!. Fletch Ir. L -$351 1 01 Pa m. Auesfing Officer tents 

